Corrosion inhibiting compositions



Patented Mar. 13, x 1951 CORROSION INHIBITIN G COMPOSITION S WernerDavid, Chester, England, assignor to Shell Development Company, SanFrancisco, Calif., a corporation of Delaware No Drawing. ApplicationFebruary 2, 1948, Se-

rial No. 5,907. In Great Britain June 30, 1947 9 Claims (Cl. 252-33)This invention relates to compositions having ability of displacingmoisture, corrosive materials and the like from corrosive surfaces. Thisinvention also pertains to the formation on such surfaces of anon-corrosive moisture resistant protective film. More particularly thiinvention pertains to corrosion inhibiting compositions suitable forprotecting metal. and non-metal surfaces by rendering them impervious towater, electrolytic solutions, corrosive fluids, gases, and the like, bydisplacing said contaminant from said surfaces and forming thereon atenacious protective film having good lubricating properties.

It is well known that moisture, corrosive fluids and gases; e. g. E28,S02, etc., readily attack not only metallic surfaces but non-metallicsurfaces and cause corrosion, rusting, pitting and other damage to suchsurface. Also, aqueous solutions when in contact with a metallic surfacereadily attack it and cause corrosion and rusting. Under certainconditions the problem of corrosion becomes exceedingly serious becauseonce started it is progressively accelerated. Thus, oils containingsmall amounts of water become very corrosive to metals in contacttherewith. .This ,is due to the fact that oils and particularly liquidpetroleum hydrocarbons are very good solubilizers of oxygen, and anymoisture present theresuch as mineral oil or gasoline, to water-islimited, ideal conditions for rusting and corrosion are set up. Thepresence of electrolytes andfor mation of corrosive decompositionproducts in oils and the like also greatly increase the rate ofcorrosivity.

Under conditions where, in addition to those enumerated, elevatedtemperatures are encountered, corrosive activity is greatly accelerated.

Thus moisture, salt sprays and other contaminants or acidicdecomposition products and corrosive gases formed during operation ofengines,

such as internal combustion engines, Diesel engines, aircraft engines,turbines and various other machinery and industrial equipment, readilyattack and rust or corrode contacting metal surfaces. The damage thuscaused is not to the metal surface alone for rust particles frequently-[break off and enter the circulating system of engines and causeplugging, clogging, and fouling of conduit lines, columns, plates, andthe line of cracking equipment, tubes, evaporators, etc.

Corrosion of alloyed bearings and other alloyed surfaces due to contactwith water can attain such an aggravated stage as to cause great fatiguestresses to be set up, which ultimately result in cracking of the metal.

The problem is equally serious when combating rusting and corrosion ofsteel drums, storage tanks used to store gasoline, hydrocarbon oils andthe like.

Moisture adhering to pickled steel, quenched steel, equipment such asinstruments, engine starters and generators on landing crafts, hydraulicsystems, machinery for metal processing and the like are alsoyextremelysusceptible to corrosion and must be protected.

Rust preventative, water displacing compositions are particularlydesired in metal rolling operation such as prior to cold rolling ofmetals. Generally, prior to cold rolling, metal sheets or strips are hotrolled, and then subjected to the following operations:

(a) A pickling operation wherein, if desired, an inhibitor is added tothe pickling bath;

(1)) A washing of the steel sheet or strip to remove the pickling agent;

(0) A drying of the sheet or strip, for example, by means of a hot airblast; followed, if desired by (d) An oiling treatment to inhibitcorrosion, particularly if the metal thus treated is to be stored forsome time prior to cold rolling.

After the material has ben subjected to these operations it is coldrolled, generally using, as a lubricant and cooling agent, a soluble oilemulsion. Subsequently, the articles are annealed, and then subjected,if desired, to a light rolling without oil through highly polishedrolls. The object of this step is to confer some degree of hardness tothe metal and also to burnish it,

thus producing a pleasing polished appearance.

The cold rolling process carried out in the above described mannersuffers from various drawbacks. Washing, drying and oiling operationsare expensive in time, labor, and cost, and moreover, unless the oilcomposition is carefully selected it is frequently found to be the causeof staining after the article has been annealed and thi is probablycaused by catalytic decompositionof oil vapors on the metal surfacebeing I annealed.

From the above description of metal rolling it can readily beappreciated that simplification of the process by elimination of thedrying, washing and subsequent oiling step is greatly desired. This canbe accomplished by use of water-displacing compositions of thisinvention prior to the cold rolling step.

been coated or treated with greases, fatty oomthereon animpermeabletenacious protective film. It is another object of thisinvention to protect metallic surfaces with a water .displacing'waterresistant noncorrosive protective film having no 1 detrimental effectupon the metal surface treat- In order for water displacing compositionsto be effective they must act rapidly and thereafter spread uniformlyand quickly over the surface treated, adhere tenaciously thereto andprotect the surface from corrosion. In addition, waterdisplacingcompositions should possess the following properties:

(1) They should be immiscible with water;

(2) They should be stable under all conditions of use or in storage;

(3) They should be non reactive with contacting surfaces being treated;

(4) They should provide protection to "15113 5111".- face treated forlong periods of time;

(5) They should possess some degree of lubricity; and

(6) They should not cause staining ,ormarring of the surface.

Countless materials and compositions have been tried for protectingsurfaces, such as metal 'sur'faces', against damage caused bywatencorrosive fluids and the like by forming-on said-surface anon-reactive corrosion'protective filmhaving lubricating properties.Metal surfaces have positions, waxes, organic compounds, e. g. or-

chemical reactive inhibitors are incapable of penetrating the surfacebeing protected and are incapable of displacing the contaminant therefrom. In cases where such inhibitors are able to form protectivecoatings on surfaces they are easily displaced by moisture or rupturereadily. They are relatively ineffective against corrosive acidicmaterials and hot gases such asare formed during operation of combustionand turbine engines and are easily destroyed when applied to surfaceswhich are subjected to high temperatures.

It is an object of this invention to-protect metal surfaces in contactwith corrosive contaminants against corrosion by treating said surfaceswith acomposition having the property of displacing said contaminantsfrom said surface and forming ed. It is still another objectof'thislinvention to provide metal surfaces with a water andacidresistantfilm which is not susceptible to rupture .cven'atelevated'temperatures and which could be readily removedwhen desired.Still another obcapableof protecting metal surfaces from corro- 'sion,-said composition also possessing lubricating properties. Another objectis to form film-.forming metal protective compositions which arestableand readily misciblewith petroleumhydrocarbons 'such aslubricating oils or other inert Organic carriers and the like. It isalso another 'objectof this invention to treat surfaces whether metallicor non-.metallic so as'to form thereon a protective film which isimpervious to moisture agents and fiimeforming agents.

4 and corrosive fluids, and which can be readily removed when desired.Other objects will be apparent from the following description.

It has now been discovered that various metals and other materialssubjected to corrosive influences can be protected simply andeifectively by treatment with a composition of matter comprisingessentially "a blend comprising a major amount of a hydrocarbon and/ormixtures of said hydrocarbons, synthetic lubricants, fixed fatty oilsand the like, and minor amounts of specially selected wetting agents,spreading The additives :of this composition must be present in a rathercritical amount, and must be present at all times during the active lifeof the composition in order "to function asJan effective waterdisplacing, noncorrosive, protective film-forming composition.

Thedispersing medium is substantially a waterimmiscible hydrocarbon or amixture of hydrocarbons such as petroleum oilsorother :type of oils, :or"their derivatives. These carriers or dispersing mediums are preferablyderived from pc- .fonate, and the like, can The used.

'troleum hydrocarbons and may include various petroleum naphtha cuts,:mineral spirits, lubritcating nil distillates, mineral seed oil,kerosene, gas oils,.mineral lubricating oil, transformer oil, white oil,kerosene .302 extract, aromatic solvents, petroleum ether, aromatic(hydrocarbons such :as benzene, :pexyl'ene, o-xylene, m-xylene, cumene,butyl benzene; paraifinic hydrocarbons, e. g. normal hexane, :dimethylpentane, octane, nonane, undecane, dodecane; cycloparaffin, e. g..cyclohexane, .methylcyclohexane, isopropylcyclohexane; synthetic oilssuch as polymerized .alkylene .oxides, polymerized olefins, esters, e.g. 2- ;ethylfhexyl sebacataetc. The dispersing medium :is usuallypresent in amounts of between "about and about of the composition,depend- ;ing upon'its viscosity,-penetrability and particularapplicationpr condition under which it is used. Preferably, the base oil'shouldnot exceed a viscosity of about 65 seconds Redwood I at -F.,and-should contain little .or no free or combined sulfur.

Additives which have the power of wetting metal and-like surfaces and ofdisplacing moisture and other contaminants therefrom so as to allowdirect contact and adherence of the protective agent-tothe'surface,aresalts of sulfonic acid such as :ammonium, amine, alkali, alkaline earthand heavy metal salts of petroleum sulfonic acid derived fromsubstantially light petroleum fractions rich in aromatics, preferablyhaving an aromatic content between-5% to 10%. Particularly suitable forforming the sulfonates are petroleum naphthas, kerosene, transformeroils and the like. The sulfonates can be formed by any conventionalmeans. For example, petroleum naphthas or kerosene fractions rich inaromatics canbe treated 'withsuitable amounts of sulfuric :acidto-obta'in sulfonic acids. These acids can be recovered :by alcoholicextraction and thereafter neutralized with alkali to form the alkalimetal salts of these-sulfonic acids. 'Sulfona'tes produced Jfonates-derived from alkylated aromatic e. g.

'butyl naphthalene sulfonate, diwax benzene sul- If desired variouspthemsalts "of :said sulfonic acids can be 75 used.

Instead of using the sulfonates derived from light petroleum fractionsas the sole wetting agent, other well known wetting agents can be usedin combination therewith. Among them can be included esters and varioussalts of organic compounds containing a minimum of 8 carbon atoms in themolecule. Particular examples are soap or salts of fatty materials orpetroleum acids obtained by oxidizing parafiin waxes, the alkali andalkaline earth metal salts, e. g. sodium,

potassium, calcium or magnesium salts of wool grease, degras fatty acid,oleic acid, stearic acid, petroleum acids-alkali salts of sulfatedalcohols having between about 8 to 20 carbon atoms in the molecule, e.g. sodium oleyl sulfate, sodium lauryl sulfate, sodium ocenol sulfate,ammonium lauryl sulfate; neutralized alkylated aromatic thereof arecottonseed oil, rape oil, menhaden oil, sardine oil and the estersthereof.

Any of the above oils can be blown by conventional means such as by airat elevated tempera Table I Per ce t s Gr. at Iodine Sap. Valueinsoluble in 15 0. Value petroleum ether Pure rape oils 0.913 to 0. 91794 to 106 -170 to 179 0 Blown rape 01ls 0. 968 to 0.975 47 to 52 209 to217. 24 to 27 Pure cottonseed oil 0.922 to 0.925 108 to 110 191 to 198 0Blown cottonseed oil 0. 972 to 0.979 56 to 65 214 to 225 26 to 29sulfates; and alkali salts of monoand polyalkyl esters ofsulfodicarboxylic acid, e. g. sodium salt of diamyl sulfo succinic acid,sodium salt of dilauryl sulfo succinic acid, disodium monocetylmonosulfo succinate, etc.

The wetting agents of this invention, such as alkali sulfonates derivedfrom low boiling petroleum hydrocarbons rich in aromatics when usedalone or in combination with other wetting agents referred to above,possess the unique property of displacing moisture from metal surfacesand in.

addition act as powerful penetrants, which however are readilydisplaceable by the protective film-forming agent of this invention.This is apparently due to the fact that these wetting agents aresubstantially miscible with and have a great afiinity for water,enabling them to remove moisture from the metal surface and allowing thepenetrant-and protective film-forming agent to come in direct contactwith the surface being treated.

The amount of preferred sulfonate wetting agent, which may be ammoniumor sodium sulfonate, referred to above, when used either alone or incombination with other wetting agents varies between about 2% and about5%, and preferably between about 2% and about by weight. When incombination with other wetting agents it is generally preferred toemploy predominant amounts of the petroleum sulfonate.

The protective film-forming,- water-displacing agents of this inventionare blown or thickened animal, vegetable and/or fish oils andderivatives thereof, such as the full or partial esters of said oil.Among such esters may be included the mono, di'and/or triglyceryl esterof capric, lauric,

myristric, palmitic, stearic, arachidic, behenic, oleic, linolein,ricinoleic acids and the like. These esters may be simple or mixed. Inaddition other fractions of said oils which are unsceptible towards ablowing treatment may be used. Oils which are suitable for use include:cottonseed oil, rape oil, kapok oil, corn oil, soyabean oil, pumpkinseed oil, beechnut oil, mustard oil, rice oil; seal oil, whale oil,menhaden oil, sardine oil,

cod liver oil, neats-foot oil, tallow oil, lard oil,

and the like; The preferred oils and derivatives These blown oils havethe unique property of displacing moisture from metallic surfaces andforming thereon a tenacious protective film. Just how blown oils performthis function is not exactly understood but it is believed that thepolar groups formed during blowing have a strong affinity for water,allowing the rest of the material to adhere tenaciously to the metalsurface and form a protective film thereon.

The protective film-forming water-displacing agents are generally usedin amounts varying from 3% to 5% by weight.

To aid in spreading the film-forming metal protective agent evenly,minor amounts of cycloalkanols having between about 5 to 19 carbon atomsin the molecule and preferably between about 4 to 8 carbon atoms, areadded to compositions of this invention. Cyclic alcohols may includecyclohexanol, 4-tertiary amyl cyclohexanol, di-tertiaryamylcyclohexanol, methylcyclohexanol, amylcyclohexanol,dimethylcyclohexanol, naphthenic alcohol, cyelobutanol, amylcyelobutanol, quinitol, carvomenthol, menthol, *beta and alphaterpineol, terpin and derivatives of cyclic alcohols such as obtained byintermolecular dehydration of an alkitol to produce polyhydric cyclicethers. By an alkitol is meant a polyhydricalcohol having atleast fourcarbon atoms and at least four hydroxy groups such as erythritols,pentitols, sorbitol, mannitol, and the like. Thecyclic alcohols need notbe used in amounts above about 10% by weight and usually range from 5%to 10%.although under certain conditions they need not exceed 5% byweight. The alcohols function as spreading agents. Thus once the wettingagent with the aid of the penetrant succeeds in wetting the surface andremoving the moisture -or other contaminant, the alcohol helps spreaduniformly the film-forming protective agent on to the treated surface.

All ingredients which constitute the present composition must be presentat all times. The absences of any one ingredient reduces the overallefficiency of the composition to such a degree as to render it almostuseless as a moisture displacing corrosion inhibiting composition. I

In order to more fully illustrate preferredcommedial-3B .7 position-ofthis invention, the .=following "finished compositions are tabulatedsherein below and should not be construed :as a limitation of thisinvention.

The'following table :further illustrates compositions of this inventionwhich-are beneficial for displacing contaminants as .described fromvarious surfaces.

Table III Components 1 'Blown'corn oil Blownsesame. oil- .r "gnu-Hour.

The components listedccn be dispersed in anysuitableIhydrocarbonsuch.as-mineraloiLikeroscne, gas oil, mineral sealoil; mineral spirits andtlielikein snamountvtheitotal of whichpreferably docs notexceed about 15%by Weight.

The following example :illustrates the applicability of compositions ofthis invention to the cold rolling .ofsteel sheets or strips.

A hot rolled steel strip wide and 0.092% thick .coil :form was passed;continuously through apicklingbath' which .was'maintained at betweenabout 35'C..ande90 C. The pickled strip was then :passed through aWashing chamber where water-was:sprayed onsaid strip. It .then is passedthrough ;a tank containing .a composi- .tion .of this inventionpreferable as noted in the Table :II above, where all the water adheringto the strip is sdisplaced. The displaced water settles rrapidly 'out'of:the composition and :is .removed from ithe bottom of the tank atconvenient :times. The strips on leaving this tank pass through feltpads in order to remove excess oil adhering tothestrip.

The strip is :then cold rolled to 0.007" thickness. This rollingoperation may be done im- ,mediately. after'thestripleaves'the oil tankor the :strip .may be .re-ooiled :and left to stand until irolling ;isconvenient. After rolling, the strip is .annealediin an'electricjfurnacean atmosphere :of cracked ammonia gas at about 700 :C.

The surface finish of strips treated :as above are remarkably "good :and:are greatly superior to the .finish of similar steels treated :by theusual process utilizing thermal dipping, oiling and soluble oil emulsionapplication during cold "rolling. Furthermoresurfaces treated withcompositions of this inventionaregfreestrom stains :and other undesireddeposits.

While the above example illustrates the preferred method .of carryingout-the process .of :cold rolling zsteel :using compositions of thisinvention, various modifications can be made which may be apparent "tothose skillediin the art of steel :rolling. Thus, suchprocesses may beconfil tinuous or batchland-the compositions of this in vention mayapplied by prayin d pping, swabbing and the like.

Besides metal surfaces, materials such ;as rubber, electrical insulation-materia1s, brake and clutch lining :and the like may be treated withcompositions of thisinvention whenever it is desired to displace waterfrom them.

.Although theessential ingredients which -c.on .stitute compositions of.this invention must be present, other additives can be included such aslinear polymer thickeners, asphalts, pour point depressor-s, :dyes,alkyl and alkyl l a nes, organic acid, e. g. oleic, stearic, :cresylicnaphthcnic acids, phenolic compounds and the like. The addition .of suchadditives are particularly desired when compositions of this inventionare required to be used as temporary lubricants.

The present compositions may be applied to a surface to be protected bya means such as immersing, flooding, spraying, brushing, trowelling andthe like. The protective film formed on said surfaces adherestenaciously enough to withstand handling, light polishing, movement andhigh temperatures for long periods of time. It can be removed whendesired by a suitable solvent'or by simply rubbing with a cloth.

The present invention having thus been fully described is not to belimited by any specific examples which have been presented herein solelyforthepurpose of illustration, but only by the following claims.

This application is a continuation-in-part of my pending applicationSerial No. 734,875 'filed March 14, 19.47.

I claim as my invention:

'1. A 'corrosionand rust-inhibiting lubricating composition adapted todisplace moisture from metalsurfaoesprior to being metalworked andprevent corrosion, said composition having the following formula andproportions:

Per cent by weight .Mineral lubricating-oil to Sodium salt of petroleumnaphthasulfonic acid derived from a petroleum :naphtha containing from 5to 10% aromatics .2 to 5 Blown rape oil 3 to 5 Methyl oyclohexanol :5 to10 '2. A corrosionand rust-inhibiting lubricating composition adapted todisplace moisture from metal surfaces prior to being metal worked andprevent corrosion, said composition having the following formula andproportions:

From about 85 to about.95

,Frcmabout 2 to about -5 ,Blownrapeoil From about -3 to about .5

Methyl 1c y:c1 oh ex anol From about 5 to about 10 3. A corrosionandrust-inhibiting mineral ilubrioating oil composition adapted to displacemoisture frommetalsurfaces containing a total notexceeding about 15% byweight, and eachlad- :ditivebeing inabout equal proportions of sodium.salt of petroleum naphtha sulfonic acid derived from a petroleumnaphtha containing from 5 to 10% aromatics, blown rape oil and methylcyclohexanol.

4. A corrosionand rust-inhibiting mineral lubricating oil compositionadapted to displace moisture from metal surfaces containing a total notexceeding about 15% by weight and each additive being in about equalproportions, of ammonium salt of petroleum naphtha sulfonic acid derivedfrom a petroleum naphtha containing from 5 to 10% aromatics, blown rapeoil an methyl cyclohexanol.

5. A corrosionand rust-inhibiting mineral lubricating oil compositionadapted to displace moisture from metal surfaces containing a total notexceeding about 15% by weight and each additive being in about equalproportions, of salt of a petroleum sulfonic acid, blown vegetable oiland cycloalkanol.

6. A corrosionand rust-inhibiting mineral lubricating oil compositionadapted to displace moisture from metal surfaces containing a total notexceeding about 15% by weight and each additive being in about equalproportions, of salt of a petroleum sulfonic acid derived from apetroleum naphtha containing from 5 to 10% aromatics, blown vegetableoil and cycloalkanol.

7. A corrosionand rust-inhibiting mineral lubricating oil compositionadapted to displace moisture from metal surfaces containing a total notexceeding about 15% by weight and each additive being in about equalproportions, of salt of a petroleum sulfonic acid derived from apetroleum naphtha containing from 5 to 10% aromatics, blown fatty oiland cycloalkanol.

hydrocarbon lubricating composition adapted to displace moisture frommetal surfaces prior to being metal worked containing a total notexceeding about 15% by weight and each additive being in about equalproportions, of a salt of a petroleum sulfonic acid derived from apetroleum fraction containing from 5 to 10% aromatics, blown fatty oiland cycloalkanol.

' WERNER DAVID.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 17,722 Millring July 8, 19302,121,475 Corkery June 21, 1938 2,182,992 Lebo Dec. 12, 1939 2,348,715Adams et al. May 16, 1944 2,359,738 Schiermeier Oct. 10, 1944 FOREIGNPATENTS Number Country Date 5 469,889 Great Britain Aug. 4, 1937

1. A CORROSION- AND RUST-INHIBITING LUBRICATING COMPOSITION ADAPTED TODISPLACE MOISTURE FROM METAL SURFACES PRIOR TO BEING METAL WORKEDWORKEDAND PREVENT CORROSION, SAID COMPOSITION HAVING THE FOLLOWING FORMULA ANDPROPORTIONS: